Many power tools use electric motors, such as brushless DC motors, to drive the tools. A brushless DC motor typically includes a rotor and a stator. Permanent magnets are positioned in the rotor. In some situations, these magnets are held in the rotor with epoxy. Epoxy, however, is inefficient, expensive, and inconsistent. For example, epoxy can be messy and difficult to incorporate into an automated manufacturing process. In addition, lots of epoxy may be wasted during manufacture. Furthermore, assembling the magnets in the rotor with epoxy relies on the skill of an operator and may result in motor failure if done improperly.